Transperineal ultrasonography assisted examination improves maternal and neonatal outcomes of forceps delivery: a propensity-score-matched analysis

Transperineal ultrasonography (TUS) is increasingly recognized for evaluating labor progression, but its contribution to delivery outcomes, particularly in forceps delivery, remains uncertain. This prospective cohort study investigated whether TUS-assisted examination improves maternal and neonatal outcomes in forceps deliveries. We included term singleton pregnancies undergoing trial of forceps at a tertiary perinatal center in Japan between 2019 and 2022. Participants were divided into two groups based on whether TUS was performed before delivery. The maternal composite outcome comprised cesarean section after failed forceps, ≥ 3 tractions required, third- or fourth-degree perineal tear, or postpartum hemorrhage > 1500 mL. The neonatal composite outcome included umbilical artery pH < 7.0, base excess < − 12, 5-minute Apgar score < 7, trauma, or NICU admission. Propensity-score matching (1:1) was applied to balance covariates. Among 403 eligible patients, 216 matched cases were analyzed. Both maternal (relative risk [RR] 0.53, 95% CI 0.29–0.97; number needed to treat [NNT] 8.9; p = 0.03) and neonatal (RR 0.47, 95% CI 0.22–0.99; NNT 10.7; p = 0.04) composite outcomes were significantly lower in the TUS group, with fewer cases requiring ≥ 3 tractions (p = 0.01). TUS-assisted examination prior to forceps delivery may improve both maternal and neonatal safety.